/*
 * Copyright 2002-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package cn.cloud.all.security.config.authentication;

import java.util.HashMap;
import java.util.Map;

import cn.cloud.all.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeanMetadataElement;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.RuntimeBeanReference;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.beans.factory.xml.ParserContext;
import org.springframework.util.StringUtils;
import org.w3c.dom.Element;

/**
 * Stateful parser for the &lt;password-encoder&gt; element.
 *
 * @author Luke Taylor
 */
public class PasswordEncoderParser {
    static final String ATT_REF = "ref";
    public static final String ATT_HASH = "hash";
    static final String ATT_BASE_64 = "base64";
    static final String OPT_HASH_BCRYPT = "bcrypt";

    private static final Map<String, Class<?>> ENCODER_CLASSES;

    static {
        ENCODER_CLASSES = new HashMap<>();
        ENCODER_CLASSES.put(OPT_HASH_BCRYPT, BCryptPasswordEncoder.class);
    }

    private static final Log logger = LogFactory.getLog(PasswordEncoderParser.class);

    private BeanMetadataElement passwordEncoder;

    public PasswordEncoderParser(Element element, ParserContext parserContext) {
        parse(element, parserContext);
    }

    private void parse(Element element, ParserContext parserContext) {
        if (element == null) {
            if (parserContext.getRegistry().containsBeanDefinition("passwordEncoder")) {
                this.passwordEncoder = parserContext.getRegistry().getBeanDefinition("passwordEncoder");
            }
            return;
        }
        String hash = element.getAttribute(ATT_HASH);
        boolean useBase64 = false;

        if (StringUtils.hasText(element.getAttribute(ATT_BASE_64))) {
            useBase64 = Boolean.parseBoolean(element.getAttribute(ATT_BASE_64));
        }

        String ref = element.getAttribute(ATT_REF);

        if (StringUtils.hasText(ref)) {
            passwordEncoder = new RuntimeBeanReference(ref);
        } else {
            passwordEncoder = createPasswordEncoderBeanDefinition(hash, useBase64);
            ((RootBeanDefinition) passwordEncoder).setSource(parserContext.extractSource(element));
        }
    }

    public static BeanDefinition createPasswordEncoderBeanDefinition(String hash, boolean useBase64) {
        Class<?> beanClass = ENCODER_CLASSES.get(hash);
        BeanDefinitionBuilder beanBldr = BeanDefinitionBuilder.rootBeanDefinition(beanClass);
        return beanBldr.getBeanDefinition();
    }

    public BeanMetadataElement getPasswordEncoder() {
        return passwordEncoder;
    }
}
